The present invention relates in general to telecommunications signal processing and more particularly to a method and apparatus for providing voice signals to and from a telecommunications switch.
The traditional circuit switched telecommunications network has been implemented to dedicate one voice line to one loop or copper pair. This has worked well for over a hundred years but does not efficiently utilize the bandwidth of the copper pair. In addition, there has been a surge in demand for second, and even third, residential phone lines. This demand is exhausting the supply of available copper circuits. Business customers also have a high demand for phone lines. To meet this demand, Regional Bell Operating Companies, Independent Local Exchange Carriers, and Competitive Local Exchange Carriers would have to build additional copper or fiber infrastructure.
New technology, such as Digital Subscriber Line, voice-over-IP, and asynchronous transfer mode techniques have created an environment where the copper pair""s available bandwidth can be more fully utilized to carry voice and data. However, traditional voice traffic is time division multiplexed, a transport architecture that segments the network bandwidth into fixed time sequenced channels. The smallest channel is equivalent to a voice line. Time division multiplexed networks work well for uncompressed analog voice but not for bursty data. If a data network needs more than 64 kilobits per second of bandwidth, the amount of one channel, two channels would be needed to carry 65 kilobits per second, resulting in bandwidth inefficiencies.
With the explosion of the Internet, worldwide deployment of Digital Subscriber Lines will rapidly accelerate over the next few years. Today, however, the penetration rate for voice over DSL is at zero percent. With the increase in their deployment, DSL is a prime candidate for implementing a multiple voice line capability for telecommunications customers. There have been recent efforts to provide voice over DSL. However, these efforts have required a GR-303 connection with a Class 5 switch for the gateway device. This GR-303 connection is available at the regional bell operating company or independent local exchange carrier level but competitive local exchange carriers would need to provide there own Class 5 switch or digital loop carrier functionality to interface with the GR-303 connection. In order to implement this functionality, competitive local exchange carriers would have to incur costly expense in providing this infrastructure. Therefore, it is desirable to migrate voice services into the data transport network in order to efficiently use the bandwidth of the copper pair and avoid expensive infrastructure changes in allowing a competitive local exchange carrier to implement an increased and efficient voice transport capability.
From the foregoing, it may be appreciated that a need has arisen to efficiently provide voice signal transport without bandwidth inefficiency. In accordance with the present invention, a method and apparatus for providing voice signals to and from a telecommunications switch are provided which substantially eliminate or reduce disadvantages and problems associated with conventional voice transport techniques.
According to an embodiment of the present invention, there is provided an apparatus for providing voice signals from a telecommunications switch that includes an input port operable to receive an unbundled analog line from the telecommunications switch, wherein a voice signal is carried over the analog line. An analog-to-digital converter unit converts the voice signal carried on the analog line into a digital format. A compressing unit places the voice signal into a compressed format. A packetizing unit places the voice signal into a packet format for transport over a data network.
The present invention provides various technical advantages over conventional voice transport techniques. For example, one technical advantage is to provide unbundled analog line ports to a competitive local exchange carrier without the need for an overlay Class 5 switch or digital loop carrier architecture. Another technical advantage is to mimic the dynamic allocation of timeslots of a standard GR-303 interface without utilizing that interface in order to provide an oversubscription capability. Yet another technical advantage is the ability to support a multitude of voice transport framing philosophies. Still another technical advantage is to provide selective compression and packetizing capabilities for versatile voice transport operation. Other technical advantages may be readily apparent to those skilled in the art from the following figures, description, and claims.